Fixing Uneven Dado Cuts

A few months ago, I bought a stacking dado set to replace my adjustable or wobbling dado blade. (I didn’t like the wobbling dado because the sides and bottom of the cut were not square.) I was very disappointed to find that the stacking dado set now leaves an uneven surface in the bottom of the cut. I found that the uneven cut was caused by the arbor on my Craftsman 3-HP contractor’s saw, which is not a constant diameter. For some reason the threaded section is turned down slightly. The blades run off center when they are stacked thick enough leaving highs and lows in the bottom of the cut. Is there anything I can do to correct or adjust for this condition?

Michael Dresdner: If, indeed, your arbor is not a constant diameter, the only practical fix is to swap it for one that is. You could conceivably make ring-shaped shims for inside the arbor hole of the few blades that sit over the threaded area, but that seems impractical to me. I’d contact Craftsman, alert them to the problem, and request a fix.